| The development of power electronics has stimulated that of marine electrical propulsion extremely, on the other side, because of the non-linear characteristics of power electronics devices, lots of harmonics has been brought into marine power system, the losses of devices and routes on the ship are increased, the quality of marine power system is worsened, and the safe and saving navigation of the ship is influenced. How to control the harmonics and make it conforms the demands of marine power system harmonics distortion rate of CCS is a practical realistic issue currently.Active Power Filter has overcome the shortcoming of Passive Power Filter which could only eliminate the specific order of harmonics. It could exam the harmonics from time to time and inject the compensating current to the power system to eliminate harmonic currents. The structure and principle of APF has been investigated in the essay, the control method of voltage regulator in the DC side of the main circuit and that of tracking circuit of order currents have been researched deeply, and the regulated APF has been applied to electric propulsion ships, all these researches to APF are of some significance in the field of practical engineering applications of electric propulsion ships.In order to increase the robustness of capacitor voltage in the DC side of APF, adaptive neural-fuzzy control combined with regular PI control has been used together in the hybrid controller and an excellent result has been achieved. On the other hand, so as to improve the performance of hysteresis tracking controller, the traditional hysteresis tracking controller has been replaced by the neural network controller in this essay, but the result carried out by MATLAB/SIMULINK shows that the performance of harmonics suppression of re-equip APF hasn’t been improved apparently. Based on these, a new hybrid intelligent controller has been proposed in this essay, first, genetic algorithms have been immigrated to neural network controller, second, the switching status of the main circuit of APF has been optimized, at last, neural network control has been applied, it has been showed through simulation that the performance is excellent.In order to exam the dynamic performance of the intelligent controlled APF, a integral model of marine electric propulsion system has been set up in MATLAB/SIMULINK, and different working conditions of APF have been simulated accordingly, the result shows that the performance of harmonics suppression of intelligent controlled APF proposed in this essay is excellent, and the dynamic performance of the whole system has been improved apparently. |
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